Germany plans to widen the security perimeters around its remaining nuclear power plants, the environment ministry said Monday, nearly three years to the day after the Fukushima disaster.

The reactor meltdowns and explosions at the Japanese plant on March 11, 2011 prompted Germany to become the first major industrial power to announce it would phase out nuclear power generation.

The government said Monday it would now propose to the country's 16 states an extension of the core security radius surrounding reactors to five kilometres (three miles) from two kilometres currently.

Germany's states are responsible for nuclear security and the area defined would be evacuated in case of a serious accident and see iodine tablets distributed to the affected population.

An intermediate zone in which people would would have to be evacuated within 24 hours would expand to a 20-kilometre radius from 10 kilometres currently.

The recommendation figures in a report by the commission for protection against radiation, an independent watchdog that advises the government.

The commission was tasked with reviewing nuclear security procedures in the wake of the Fukushima catastrophe.

Germany still operates nine nuclear power plants, which are to be shut down by 2022.